Process and apparatus for dyeing or performing related



Nov. 9, 1954 R. s. E. HANNAY ETAL PROCESS AND APPARATUS FOR .DYEING OR PERFORMING RELATED PROCESSES UPON TEXTILES usmc MOLTEN METAL 5 Sheets-Sheet 1 Filed Feb. 5, 1954 BYM, 94 11 4 ROBERT s. E. HANNAY WILLIAM mLBY,

ATTORNEYS.

R. s. E. HANNAY ETAL ,9 PARATUS FOR DYEING OR PERFORMING RELATED PROCESSES UPON TEXTILES USING MOLTEN METAL 5 Sheets-Sheet 2 P A D N A S m 9 4% 5R 9P3 l b 9 w W N n F A lorney:

R. S. E. HANNA! ET AL Nov. '9, 1954 PROCESS AND APPARATUS F OR DYEING OR PERFORMING RELAT PROCESSES UPON TEXTILES USING MOLTEN METAL Filed Feb. 3, 1954 5 Sheets-Sheet 5' FIGS;

M v y fl 7 :1 Hurm'ya NOV. 9, 1954 R s E HANNAY ETAL" 2,693,995

PROCESS AND APPARATUS FOR DYEING OR PERFORMING RELATED PROCESSES UPON TEXTILES USING MOLTEN METAL Filed Feb. 5. 1954 5 Sheets-Sheet 4 ROBERT s. E.HANNAY,$

WILLIAM KILBY,

ATTORNEYS.

INVENTORS.

Nov. 9, 1954 R. s. E. HANNAY ETAL 2,693,995

PROCESS AND APPARATUS FOR DYEING 0R PERFORMING RELATED PROCESSES UPON TEXTILES USING MOLTEN METAL Filed Feb. 3, 1954 5 Sheets-Sheet 5 INVENTORS:

aw v, N a R m m K; (r EK m mm w b 1 WW 7 B United States Patent O M PROCESS AND APPARATUS FOR DYEING OR PERFORMING RELATED PROCESSES UPON TEXTILES USlNG MOLTEN METAL Robert Stewart Erskine Haunay, Midlothian, Scotland, and William Kilby, Lancashire, England Application February 3, 1954, Serial No. 407,962

Claims priority, applicationGreat Britain January 14, 1946 36 Claims. (Cl. 8-34) The present application is a continuation-in-part of each of the following copending applications: Serial Number 722,042, filed January 14, 1947, which was allowed May 13, 1953, now forfeited; Serial Number 46,804, filed August 30, 1948, now abandoned; Serial Number 90,995, filed May 2, .1949, now abandoned; Serial Number 90,996, filed May 2, 1949, now abandoned; and Serial Number 90,997, filed May 2, 1949, now abandoned.

This invention relates to processes for the modification of textile materials by treatment with aqueous liquors at elevated temperatures and to apparatus for carrying out such processes. The term textile materials is intended to embrace various materials as used in the textile industries, for example,'fabric, felt, yarn, or webs of material, including, for example, cotton, wool, linen, acetate-rayon, nylon, viscose, silk, cuprammonium rayon, Orlon, a polyacrylonitrile fiber produced by E. I. duPont de Nemours & Co., Terylene and other natural or artificial materials, as well as glass fibers and material including the same. The term textile is not intended to restrict the scope of the invention to woven material. Such textile materials are characterized by possessing the property of being penetrable by conventional aqueous liquors used in dyeing and related processes, e. g., aqueous dye liquors and aqueous dye developing liquors.

This invention particularly relates to new dyeing methods and continuous dyeingapparatus.

FIELD OF THE INVENTION The textile industry has many and varied processes for the treatment or modification of textile materials.

One generalv type of such treatment processes is that in which the textile materials are modified by treatment with aqueous liquors at elevated temperatures. This includes such operations as dyeing, moth-proofing, scouring, shrinking, size setting, rendering water-repellant, rendering crease-resistant, and the like. Each of the specific procedures which fall within the stated general type present special problems. This is especially true of those operations which come under the classification of dyeing. l

As an example of problems associated with dyeing are the difi'iculties experienced in obtaining uniformity of color over the entire area of the goods. Thus, in the dyeing of cloth, for example, by a padding process, the cloth is usually passed through the dye liquor and subsequently through a mangle nip to express surplus liquor. Irregularities in the thickness of the cloth cause unequal squeezing with a tendency to express more liquor from the thicker than the thinner parts. This ultimately results in unevenness in coloration of the cloth.

Unevenness in coloration of fabric in dyeing procedures takes place also in the type of process where extrusion of dye liquor is etfected by a suction extractor which depends upon the porosity of the cloth for the evenness of the results. This is also true in the case of a third dyeing process used in a dyeing jig or vessel in which the cloth is run through the liquor a sufficient number of times to obtain the desired result. However, because the control of this process is not easy due to difiiculties of maintaining ideal conditions of volume, temperatures and dyestuff concentrations, uneven coloring is hard, if not impossible, to eliminate.

In operations in which textile materials are treated With aqueous liquors at elevated temperatures,'heating of the material under treatment also presents serious problems. At present there are three main procedures employed to 2,693,995 Patented Nov. 9, 1954 heat textile material. First is the type in which heat is transferred to the textile or like material by convection.

which a cylinder machine is employed and the material.

contacts the hot surface of the cylinder. Although such procedures are elficient from a thermal viewpoint, they suffer from the presence of airand in many cases cause an undesirable glazing of the surface of the cloth.

The third distinct type of heating operation uses radiant heating with heat being conveyed to the material by radiation. This type of operation is not only costly, but also suffers from the presence of air, particularly undesirable where dye liquors active with oxygen are used.

Most procedures used in the treatment of textiles with aqueous liquors at elevated temperatures also involve a step where pressure is applied to the textile material. For example, in dyeing, a pressure application step is generally required to remove excess of dyeing liquors or the like. The established practices for pressure application in this field use either rollers or fiat plates. Aside from the problems of uneven pressure particularly with cloth of irregular thickness, as indicated above, such procedures generally result in some defacement of the surface of the material.

Aside from these problems which are experienced broadly in the treatment of textile materials with aqueous liquors, there are certain problems which are rather specific o the dyeing of textile materials. For example, the expense of the dyestuffs employed make it desirable to reduce the volume of unconsumed dye liquor remaining at the end of a run to a minimum. It is further desirable to enable accurate matching of shades with a minimum of eifort and expense. 'It is still further of great benefit to avoid tailing difliculties without the use of a feed liquor of diiferent composition from that of the original dyebath. Also, efficient commercial operation requires an ability to change dye baths with only a very small shut down time and to enable a great variety of treatment operations to be performed on the same equipment. Further, since most dyestuffs are of only limited solubility, it is a great advantage to be able to operate efficiently and satisfactorily with dye baths at elevated temperatures at which increased solubility of the dyestuff is achieved enabling more dyestulf and hence deeper shades to be attained in a single pass.

Other factors which may influence greatly the final results obtained in a dyeing operation include: the preparation which the cloth has received prior to dyeing, e. g., whether wetting agents or the like have been applied to the goods, the speed with which the cloth is run through the dyeing apparatus, the speed with which dyestufi llquors penetrate or are absorbed by the material under treatment, the adaptability of a particular process to treat materials composed of a variety of different filaments, i. e., union materials, and the ability of dye procedure results obtained on test or laboratory scale to be duplicated on a commercial scale.

OBJECTS A principal object of this invention is the provision of new methods for the modification of textile materials by the treatment thereof with aqueous liquors at elevated temperatures and the provision of new apparatus for use in connection with such procedures. Further objects include:

1. The provision of new methods for dyeing textile materials.

2. 'The provision of new forms of dyeing apparatus.

3. The provision of new procedures for the treatment of textile materials with aqueous liquors at elevated temperatures which allow for uniform heating of the textile material, even with substantial variations in the thickness thereof, and at the same time eliminate air contact with the material during the high temperature treatment, all at low cost and at a high thermal efiiciency.

4. The provision of aqueous liquor treatment operations for use with textile materials whichpermit the uniform application of pressure thereto substantially independent of the thickness or configuration of the textile material under treatment.

5. The provision of new dyeing methods in which the volume of dyeing liquor per unit of cloth is maintained substantially constant during the critical stage of effective fixation of the dyestuif material upon the goods without evaporation of the dyeing liquor or similar variation thereof during said criticalstage.

6. The provision of new dyeing operations in which a.

uniform quantity and strength of dye per unit of fabric is insured substantially independent of the configuration or thickness of the goods.

7. The provision of new dyeing procedures which enable deep shades to be applied with a single pass of the fabric through the dye liquor.

8. The provision of new dyeing procedures which are relatively independent of the prior treatment or preparation of cloth and which do not require superlative cloth preparation for satisfactorydyeing results.

9. The provision of new dyeing methods which are relatively independent of the speed with which the cloth being dyed is passed through the dyeing equipment and which allow cloth to be dyed at very high rates of speed, c. g., dyeing times of as low as two seconds.

10. New dyeing methodswhich permit extreme uniformity of shade or coloration to be obtained with all varieties of textile materials, even those which vary greatly in thickness throughout a given area.

11. The provision of new textile liquor treating apparatus which is comparatively simple in construction and easy to operate even for unskilled technicians.

12. The provision of new dyeing methods and dyeing apparatus which make possible the dyeing of union materials to give products having good uniformity of shade between the various fibers of the materials even when dyestuffsare employed which normally would give different depths of shade with the different fibers of which the union material is made.

13. The provision of new dyeing methods which make possible the use of increased temperatures to increase the afiinity of the dyestuff for the fabric and the usable concentration of dyestulf in the dye liquor.

14. The provision of new dyeing operations and apparatus for use in connection therewith which makes possible the exclusion of air from the time the dyestuff on the cloth is in reduced form until the dyestuff has been maintained atelevated temperature for a sufiicient time to substantially complete the fixation of the dyestuffs.

15. The provision of new apparatus for use in the dyeing of textiles which eliminates the use of pressure rolls or plates or similar mechanical squeezing or liquor expressing means.

16. The provision of textile dyeing apparatus which makes it possible to match the shades obtained on laboratory size apparatus without guess work or need for empirical adjustments when. transferring to commercial or plant-size apparatus.

17. The provision of such apparatus and methods which make it possible to change from one dyeing shade to another substantially instantaneously and without need to discard large quantities of valuable dyeing liquors and which also permit cleaning-down to be done very simply.

18. The provision of, such. apparatus and methods capable of handling very large outputs of cloth at economically high speeds, e.- g., speeds of 100 to l20 yards per minute, in a continuous fashion giving products of good shade-matching, uniformity, penetration and levelness throughout.

19. The provision of new methods and apparatus which enable dyeing with different classes of vat dyestuffs or of different sulphur dyestulfs, to be carried out simultaneously under the same conditions of temperature and alkali concentration in contrast to generally known procedures which are highlysensitive to temperature conditions and make it exceedingly difficult, if not impossible, to use certain vat dyesin conjunction with one another in a single dyeing.

20. The provision of dyeing methods which are usable with vat dyestuffs dissolved in an appropriate amount of alkali and reducing agent as well as the usual pigment padding type of operation in-which the textile material is impregnated with an'aqueous suspension of undissolved vat colors and subsequently treated in a. vessel with an 4,. appropriate amount of alkali and reducing agent in order to solubilize' the color in situ.

21. To enable the employment of aqueous treating liquors maintained as a floating layer upon a bath of molten metal at a temperature not greatly in excess of the melting point of they metalof the bath without encountering solidification of the metal of the bath which defaces the fabric being treated.

22. To enable high speed passage of textile materials through a molten metal bath the metal of which is solid at room temperature withoutencountering solidificatiom of the metal of the bath.

23. To enable aqueous liquors which are adversely atfected by elevated temperatures to be satisfactorily employed atthese temperatures.

24. To enable prolonged continuous operation to be performed employing aqueous liquors containing hydrosulphite without encountering the formation of sludge on the surface of the molten metal bath..

25. To stabilize hydrosulphite containing aqueous liquors against the tendency of the hydrosulphite to de compose at elevated temperatures to form decomposition products which attack the metal of the molten. metal bath and forma sludge.

26. To maintain. the surface of the molten metal, bath where the textile material enters the same free of air oxidation products without resort to the use of inert gases.

27. To avoid the tendency of the textile material to pick up particles. of molten metal and sludge as it emerges from the molten metal bath.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description andspecific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

GENERAL DESCRIPTION liquor into said materialby the uniform pressure of the:

molten metal effecting a' squeezing action thereon, with said molten metal being heated to a temperature above about 60 C. and below a temperature at which any' substantial ebullition of aqueous liquor from said cloth will take place, and finally passing said textile. material out of said bath of molten metal with said textile material still containing a substantial portion of aqueous liquor therein. The molten metal is selected so that: it does not chemically react with the textile material or the aqueous liquor thereon.

Preferably; the new method is employed for the dye-- ing of textile materials. In such cases, the dye liquor,

or dye reducing liquor, as the case may be, is floatedi upon the surface of a bath of molten metal so that when the material under treatment leaves the heating a .layer and enters the moltenmetal bath, the material with the liquor carried with it may be passed downwardly to a substantial depth in-the bath of molterrmetah and be subjected therein to elevated temperatures with-- out any substantial evaporation of dyeing liquor from the textile material. Preferably the molten metalv bathv consists of Woods or a similar low melting alloy of lead and bismuth having a melting. point below about. C. and said metal is preferably maintained in'. molten condition at a temperature between about 80 and C. Also, it ,is preferable to have the major-portion of the-pathof the:fabric through the molten metal vertical, on nearly so.

Further accomplishment of' theseobjects is alforded by the provision of: textile treating apparatus-which:

comprises a substantially U-shaped' chamber containing molten: metal in-the chamber having-a-meltihgpointbelow 100" C. and preferably above about 60 C. Lower melting metals such as mercury may be usedpbut, as

is well known, it is dangerous to work with mercury in heated condition because of the noxious vapors which are emitted. The U-shaped chamber is provided with means for heating the metal in the chamber and container means are provided-at the inlet of said chamber to receive aqueous -treating liquors immiscible with said molten metal. The container is suitably shaped and positioned to permit the aqueous liquor suppliedthereto to be floated as a layer on thesurface of said molten metal. Preferably, such apparatus includesmeans for continuously feeding a continuous web of textile material into the inlet side of the chamber and means for withdrawing the continuous web from the outlet side of the chamber. In the more desirable forms of the apparatus, said aqueous liquor containing means consists of an open bottom trough positioned at the inlet end of the chamber with the lower end'of the trough extending slightly below the surfaceof said moltenmetal bath and with a conduit connected to the trough for introducing the aqueous liquor onto the surface of the volume on the surface of the metal bath with additional quantities of aqueous dye liquor being supplied thereto as it is absorbed by the textile material passing downwardly therethrough. Preferably, the floating liquor is employed in the form of an elongated vertical column with additional quantities of liquor being supplied to the column in substantially continuous fashion so as to maintain the height of the column uniform within a variation of 5%.

f Moreover, when dyeing with vat or sulphur dye liquors a reducing agent such as sodium hydrosulphite is added to, the floating dye liquor, or-where the dye is first padded unreduced, the reducing agent is apart of the aqueous liquor which floats on the molten metal bath. In either event, prolonged heating of the. aqeuous dye liquor or aqueous dye reducing liquor leads to the formation of decomposition products which attack the molten metal with formation of sludge, and this may adversely affect the dyeing results on the material.

,Still further, if the freezing point of the molten metal is not much lower than the maximum permissible tem-.

perature of the treating liquor, the temperature of the liquor must be maintained accurately and continuously in order to prevent solid particles of metal forming and interfering with uniform application of the liquor to the material. An aqueous liquor, for example, should not be above 100 C., while the freezing point of the molten metal may in some cases not be greatly below that temperature.

Accordingly, the layer of liquor floating on the molten metal bath is maintained at a very-small volume by substantially continuously replenishing the floating liquor with fresh liquor which is heated from a'temperature of about 25 to 30 C. to the temperature of the floating liquor, e. g., 80 C., just prior tov being introduced to the layer floating upon the molten metal bath. Such procedure enables the floating layer of liquor to be maintained without variations in temperature, volume and strength of a magnitude likely to adversely affect the treatment and the length of time during which a hydrosulphite containing liquor is maintained at elevated temperature is kept short so as to reduce decomposition and resulting formation of sludge to a minimum. Still further, the temperature ofthe liquor in the floating layer is prevented from falling undesirablylow.

Also if the textile material entersthe layer of liquor floating on the molten metal in unheated condition, even if the floating liquor is itself heated, the textile mate-- rial may sti l enter the molt n metal bath at a temperature s flicient v low to solidify r freeze the metal of the bath. This may cause solid lumps or particles of the metal to be formed on the textile material at the interface between the metal and the dye liquor, and may interfere with the uniform application of the dye liquor to the material. This may also occur where the dyestuif is padded upon the textile material prior to entry of the padded material in the aqueous dye reducing liquor floating on themetal bath entry surface.

Accordingly, it is preferred to heat the textile material so that the material may enter the molten metal bath at a temperature above the freezing point of the metal bath. 'Naturally, the treating liquor floating on the surface of the metal bath is taken into consideration, and hence, the temperature of the material prior to treatment with the floating liquor should be such that the temperature of .the combined textile material and treating liquor prior to entry to the metal bath is above the freezing point of the metal bath.

It is desirable, particularly when operating with vat dyestuffs in which the textile material is subjected to the action of liquors containing hydosulfites, which treating liquor floats on the surface of the molten metal bath, to incorporate in the treating liquor an anti-oxidant substance which retards the rate of formation of alkali sulfides from the hydrosulfite. Reducing sugars, such as glucose, are particularly advantageous for this purpose.

Still further, it has been found that there is a tendency for the textile material as it leaves the molten metal bath to pick up scum or particles of the molten metal. To prevent this, an aqueous liquor is floated on the surfaceof the molten metal bath at the exit side where the textile material leaves the bath. The aqueous liquor whichis floated on the exit surface of the molten metal bath is selected so that it is inert to the metal of the molten metal bath and is not deleterious to the dyeing liquor on the fabric. Additionally, the aqueous treating liquor floating at the exit may contain salts of other chemicals which assist the fixation of the dyestulf or neutralize the previously applied dye liquor. In this regard, when dyeing direct dyestuffs, the exit liquor may contain common salt, Glauber, or weak acids such as formic or acetic acid. I

' DETAILED DESCRIPTION A more complete understanding of the new procedures and apparatus comprehended by this invention may be had by reference to the accompanying drawings in which:

Figure 1 is a diagrammatic side view of one form of the apparatus designed in accordance with the present invention.

\ Figure 2 is. a vertical fragmentary transverse sectional View on an enlarged scale through the molten metal bath section of the apparatus of Figure 1.

:Figure 3 is a fragmentary elevational view of one of the sides of the bath section shown in Figure 2.

Figure 4 is a cross-sectional view on the lines 4-4 of .the molten metal bath comprises troughs arranged in tandem with the liquid level above the path of the material throughout, this view also showing filling blocks instead of correspondingly shaping the interior of the molten bath.

' Figure 9 is a fragmentary elevation of open mesh wire gauze which may be used to line the sides of the molten metal bath in lieu of the narrow projections shown in Figures 3 and 4.

Figure lO is a sectional view on the line 10--10 of Figure 9 showing the wire gauze anchored to the wall of a molten bath as by welding.

Figure "11 is'a diagrammatic sectional side view of a modified form of apparatus in accordance with this invention showing the continuous treatment of a length of cloth with one form of a cloth heater, automatic means for heating aqueous dye liquor prior to automatically introducing itupon the surface of the molten metal bath and the provision of an aqueous liquor floating on the molten metal bath where the cloth emerges from the bath.

Figure 12 is a sectional detailed view showing cloth passing through another form of cloth preheater.

Figure 13 is a sectional detailed view showing cloth passing through yet another form of cloth heater for use in the apparatus of Figure 7.

opennes Referring'now to Figured, the cloth- 11 is unwound from rolls 2 and is passed over -rolls-3'-directly into-the bath indicated as a whole at4having-a single entrypass at4a and a single exit passat 4b, around .-a bottom roll-5;

The dyedcloth then passes'a-way to roll 6.

Dyeing liquor is arranged tofioat on the surface/of the metal bath, as will be more fully explainedherein after'in connection with Figures-2, 5 and 6. The'level of'thedye liquor is kept constant in the form ofappa ratus for controlling a supply of liquor from a main:

supply tank 8.

Cloth being treatedin the'apparatuswof Figure 1' may take an alternative route as shown in dotted lines at 9 by passing through a padding trough 10in order totake up dyeing liquor after'which the cloth passes-through niprolls 11 down into the-molten metal bath- 4-'-as previously described. Inthis case, the level of the liquor in the trough 10 is maintained constant as by a float.

closely together opposite each other and mounted-upon a frame including base 15 and-angular top members 16.

A central partition 17 is provided between theside plates 13 and 14 dividing the apparatus into two separate vertical channels. This structure allows the molten bath proper to be maintained at a minimum of volume thereby requiring a minimum amount of the-relatively expensive bath metal and requiring a minimumof heating.

The path of the cloth through the molten metal bath is:indicated by 4a and 4b. Heatis communicated tothe molten metal 18 at intervals throughout the-whole of the bath by a series of steampipes 18- located on each side of the cloth passageway throughout the entire length thereof. The molten metal intimately heats the cloth without chemically reacting therewith or with the dye liquor and furthermore it does not absorb the dye liquor. Atthe. same time, the success of the present invention is due: inpartto the unique. discovery that, if the cloth is maintained impregnated or wet with aqueous treating liquorduringpassage through the molten metal bath, which istachieved by floating the impregnating liquor on the molten metal bath, then molten metal is not absorbed by ghehcloth nor will the cloth be marked by the metal of the Itwill also be evident that utilization of molten'metal not only enables simple, accurate and efficient application of heat, but, depending upon thedepthand specific gravity of the molten metal bath, the pressure applied to the cloth may be controlled without increasein the pressure of the air surrounding the metal bath. I'nthis way it is possible to impart to the clotha uniform squeezing action of any desired pressure throughoutrthe entire surl face area of the cloth regardless of the. irregularities in configuration or thickness of the cloth.

It is preferred to pass the cloth being treated through the molten metal bath in a substantially vertical elongated path. This is because it hasbeen found that if. the. cloth is caused to move through the molten metal ina. path other than substantially vertical, there is a strong tendency for the material to float upwards. This dis-. placement of the material relative to a verticaliroute through the bath causes undesirable tension on'the cloth and will produce marking of the cloth should the-cloth.

rub against the'walls of the bath. Asthose skilled in the art will appreciate, the vertical passage of the goods need not be absolutely so and there is no inherent objection to moving thematerial in a path slightly away fromthe vertical or in moving the textile-like rnaterial around the underside of a roller, such as roller 5' of the apparatus of Figure l or 2 as in such cases any flotation effect-mere- 1y tends to keep the material in contact with the roller.

The top 19 of the bath 4 is of enlarged width and the surface of the molten metal bath is indicatedat 20. Within this expanded region, there is located'a dye b01022 provided with a downwardly extending, open-ended con is exposed to the atmosphere, and through the aqueous layer to pass directly -therefrom intothe molten metal bath I without -'exposure 1K1 the -atmosphere.

As indicated in connection with Figure 1; the dye liq uoris=supplie d to the=dye box-22by; means of a; control nected to the-supply tank '8. Automatic. means for maintaining the level of 'the molten' metal'bathconstant may beprovided'also; if desired, but "this is generally unnecessarysinceit' has been found that loss of molten metal from" the bath maybe -m-ade negligible;

As-can be seen from the drawings, theaqueous dye liquor or" 'aqueous dye reducing liquor floats uponthe surface of-the moltenmetal b'ath, It has-beenzdiscovered that byoperating in this fashion-thecloth=containsa preexact amount'of treating liquor taken up by'the cloth and at thesame time air=is excluded from the cloth from the time during the' time-the dyestuff on the-cloth is in reduced formuntil fixation'of thedyestutf has been substantially completed.

The treating bath 4 and the other sections of the apparatus, such as=the dye liquor box 22; are formed relatively long in relation to their width so as to accommodate the'entire widthofcloth to be'treated by'the apparatus.

Figures 3 and 4 illustrate specific-constructions for the walls'i13 and 14 and'central partition 17 designed to prevent binding -ofthe cloth on the adjacent surfaces of the .parts 13'; 14jand:1'7.' The'semeans'consist of'internal narrow projections on the surfaces 13;.14"and 17 spaced by" recesses, the recesses preferably being hydraulically interconnected; Inthis'way, the molten metal may pass' at all times between the-cloth andthesurfaces of the sides 13'and14and' the central partition lTso as to balance the pressure on each side of the cloth. This-may conveniently be effected by: providing elongated serrations extending from top to bottom of'the' bath proper on thesurfaces13, 1'4 and l7; theserrationsbeing inclined slightly off the vertical, forexample at about 2% as indicated in Figures 3 and 4; It hasalso been found de sirable that these serrations on opposite faces should be inclined in :opposite directions in order not-to deflect the cloth. For example, if the serrations-on the inner surface. of' 13 are'inclined toward-the right, then the'serraations on the opposite inner-face of the partition 17 are inclined towards'the left; A-similar arrangement is made upon the exit side of structure 4. As an example ofdimensions; the serrations-maybe about fit" between their" aprces and with a depth of about /3";

The preferredformof the dye box 22is shown in more detail in Figures'iS and 6'. As canbeseen, the dye liquor entersthroughinlet'24 and'passes round to each longitudinal'side of the dye box2ll The dye liquor enters the interiorrofthe dyeibox through-a series'of holes25 in each side of the box. The holes 25 increase inarea fromftheznear 'end to .the remote" endin'order to equalize 1nflow"along. the length ofthe box;

In addition to orinstead'of'heatingthe molten metal by internal pipes-such sis-'18," the metal may be led'externallyxthrough a heater' and may also'be filtered.

ln-a modification andreferring to Figure 7 of the-drawing;.the b'ath 4 may comprise=a series of rolls sub'stanhally or" wholly immersedin'the bath of molten metal, the rnaterial passing'thereover 'SiIlUOHSlYthlOUgh the bath, thet-materialitravelling downwardly,- laterally and upwardlyas shown by thc'arrows in the molten metal bath; the rollsmay thus fill a' large proportionofthe bath volume.

As aforesaid; the treating liquor-floatson' the surface of the; bathof molten metal.

Itrhas been found that when cloth, for example, is passed throughfa' hath' ofdiquid metal as described abovez (a)' A squeezing eifectis obtained which depends on the specific gravity of' the metal and the depth of the bath. 'The" pressure is evenly'distributed anddoes not deface the cloth.

(b) The metal positively prevents theescape of any treating liquor previously applied to the..cloth and ensures that the whole. of such liquor applied is in fact used for the process desired.

(c) The cloth and any liquor contained in it attain the temperature of the metal almost immediately and it is therefore possible'to control the optimum conditions for the reaction.

(d) The exclusion-ofainduring' the' process has'the fiber is restricted because of the low ratio of dye liquor to fabric; therefore a more universal use of vat dyestuffs for wool is permitted, and damage by the alkali is restricted.

As an example of the advantages quoted above, a heavy cotton fabric was pigment-padded with unreduced vat colors and passed through the usual reducing agents into a bath of mercury six inches deep at 110. Development was complete in 30 seconds as compared to the 30 minutes to 1 hour necessary when the process is done in a vessel under hitherto exlstmg methods.

Where a long immersion is required without the material contacting air, the molten metal bath may comprise troughs arranged in tandem, as shown in Figure 8, with the liquid metal level above the path of the material throughout and the material traveling downwardly, laterally and upwardly in the molten'metal bath as indicated by the arrows.

The bath of molten metal required to apply the heat and pressure may be maintained at the minimum by inserting filling blocks 31 in the spaces in the bath not occupied by the material, instead of by correspondingly shaping the interior of the bath as described and shown above, suitable rolls 32 being provided over which the material passes from one trough to the next.

For textile printing, the color will be applied to the cloth prior to entry to the bath, in any known manner, and the cloth is then passed through the bath in similar manner to that indicated above, with the application of dye developing liquor at the surface of the metal bath.

Some examples of dyeing processes in accordance with the basic teachings of the invention as previously set forth will now be described.

For instance, Caledon Blue R. N. S., the vat dyestulf Indanthrene, Color Index 1106, normallydyed at 60 C.

gave excellent results when dyed in the liquid metal bath at 108 C. Similarly, Caledon Red B. N. S., the vat dyestuff 1,2 Anthraquinonenaphthacridone, Color Index 1162, normally dyed at 20 to 25 C. also gave excellent results when dyed in the liquid metal bath at 108 C. Further, the amount of caustic soda required normally hitherto for Caledon Blue R. N. S. was about 6 gms. per liter and for Caledon Red B. N. S. about 2 gms. per liter. Both can now be dyed in the liquid metal bath aforesaid with the same quantities, and large variations in this quantity do not appreciably affect the results, no important diiference being observed in either case within the range of 8 to 20 gms. per liter, the amount selected being independent of the nature of the dyestutf and sole- 'ly dependent on the amount of reducing agent used.

It thus becomes possible to mix vat dyestuffs of different classes in a common dyeing stage. i

The invention is applicable to both of the types of dyeing of vat dyestuffs mentioned previously, e. g., application of the dye in reduced form or padding of the dye in unreduced form, followed by the application .of a dye reducing liquor. However, the invention has the important advantage that when the dyestuflf is applied in the reduced form. it is not essential that the whole of the color should be in solution when the fabric is impregnated.

Examples of the three abovementioned dyeings will now be described employing a low melting point alloy having a eutectic composition approximately as follows:

tin. 13.3%; lead, 26.7%: bismuth, 50% and cadmium,

10%. This metal alloy has been found to be especially suitable for useas the molten metal and this composition has a melting point of about 70 C.

Example I Dry prepared fabric is passed into the liquid metal bath (temperature 103 C.) through an aqueous dyebath containing 100 gms. per liter Caledon Blue R. N. S.,

:10 gms. per liter Calsoline oil (Imperial Chemical Industries Limited), a highly sulphonated oil in aqueous solution, 200 gms. per liter caustic soda, 10 gms. per liter sodium hydrosulphite, 4 gms. per liter Formosul C. The passage through the liquid metal bath occupies fifteen seconds and a satisfactory shade is obtained. Compared with the normal method, there is a large saving in dyestuffs and chemicals.

Example II Example III Dry prepared fabric is passed into the liquid metal bath (temperature 108 C.) through an aqueous dyebath containing 50 gms. per liter Caledon Blue R. N. S., 50 gms. per liter Caledon Red B. N. S., 10 gms. per liter Calsoline oil (Imperial Chemical Industries Limited), 20 gms. per liter caustic soda, 20 gms. per liter sodium hydrosulphite and 5 gms. per liter Formosul C. The passage, occupying fifteen seconds, produces the fast blue grey color which is to be expected in a combined shade of these two dyestuffs.

After oxidizing and soaping, all these dyeings possess the high standard of fastness to washing normally associated with this type of dyestutf.

Example IV In a further example of the invention utilizing the metal alloy specified above as the bath medium, the alloy is heated to the temperature 102 C., the fiat sides of the vessel being lined ith 10 mesh steel wire gauze 33, as shown in Figure 9. Referring to Figure 10, the gauze is shown as being anchored to the wall of the molten metal bath in any suitable manner, as by welding at spaced points 34. Cotton fabric to be developed in this machine is first pigment padded on an ordinary tworoll padding machine with 60% squeezing, using an im pregnating liquor containing gms. Caledon Blue N. S., 30 cos. Calsoline oil, and 80 gms. British gum, a degradation product of starch, 1:1) per liter. The impregnated fabric, undried, is passed into the molten metal bath through a bottomless box arranged at the surface of the bath with the lower edge immersed in the molten metal. Into this box is fed an aqueous developing liquor containing 45 gms. caustic soda, 60 gms. sodium hydrosulphite, and 10 ccs. Teepol X (Technical Products Limited), a detergent derived from mineral waxes, per liter, at a temperature of 60 C.

.Theflow of developing liquor to the box is adjusted in accordance with the absorption by the fabric, and the amount of developing liquor in contact with the fabric can be comparatively small. The passage of the fabric and feeding of the developing liquor serve to lower the temperature of the surface of the molten alloy so that ebullition of the aqueous developing liquor on contact is avoided. The passage of the impregnated fabric through the molten metal bath occupies 10 to 15 seconds, and the fabric when finally oxidized, washed, and soaped, is colored the full blue shade of excellent fastness normally associated with this dyestuff.

Example V In a further example of the invention using the same apparatus described in the previous example for the application of sulphur dyestuffs, dry scoured cotton fabric is passed into the molten metal bath at 102 C., through an aqueous dyebath containing 20 gms. Sulphol Khaki 2 G (200%), a sulphur dye, supplied by James Robinson & Co. Ltd., Huddersfield, 'England, 20 gms. caustic soda, 20 gms. sodium hydrosulphite, and 10 ccs. Teepol X per liter, supplied at 60 C. The cloth speed is adjusted to give an immersion time of 10 to 15 seconds in the molten metal bath.- The dyed fabric is finally oxidized, washed and dried.

In the treating of yarns in accordance with the present invention, it is not necessary to maintain each yarn separate from the other and a reasonable amount of bunching together of the yarns is permissible. Yarn dyeing may be performed during the passage of the yarn to the beam .from anyconvenient package and, if desired, inconjunctron with sizing. In such a process the beam of yarn can be produced in a variety of colors by dividing the said bottomless dye box at the surface of the molten metal mto sections.

Figures 11 through 13 illustrate a further improved form of apparatus incorporating additional refinements which have been discovered to give even more satisfactory dyeing of fabrics than themore basic and general form of apparatus illustrated in Figures 1 through 10.

In the form of apparatus shown in Figure 11, cloth 1 in continuous length passes in' the direction of the arrows over steam cylinders 35.adapted to heat the heaviest cloth traveling at the highest speed to a temperature somewhat above 70 C. The apparatus may also be used for lighter cloth-at lower speeds and the heating of the cloth may be controlled by varying the pressure of the steam upon the heating cylinders although this is not critical sinceoverheating of the cloth is not serious when temperatures corresponding to 15 p. s. i. steam pressure are employed.

In Figure 12, an alternative arrangement for cloth heating consists of a casing 36 through which the cloth 1 passes and through which hot air is forced by a fan 37, the air temperature being such that the arrangement may be used for lighter cloth at lower speeds without concern for overheating.

In Figure 13, a further alternative arrangement for cloth heating consists of pairs of opposed electrical radiant heating units 38 spaced along the cloth length, the cloth passing between the units of each pair of radiant heating elements. Control of the cloth temperature is obtained by switching the radiant heating units on or off selectively.

The heated cloth 1 for the purposes of dyeing passes over the guide rolls 39 and 40 and directly down into the molten bath vessel 41 through the single entrance pass 41A, around the bottom roll 42, out the single exit pass 41B and away over the guide roll 43.

The dye box 44 comprises an open bottom metal box.

extending into the molten. metal bath below the top surface 45 thereof and contains the dye liquor 46, which floats as a layer on the surface 45 of the molten metal.

The layer of liquor 46 is maintained at a comparatively small volume and as it is absorbed by the cloth passing through the apparatus, it is substantially constantly and automatically replenished with fresh liquor heated to the temperature of the liquor 46 in order to maintain the condition of the liquor in said layer such that variations in temperature. volume and strength of a magnitude likely adversely to affect the treatment are avoided.

The replenishing liquor is heated as it is supplied to said layer. In this way the treating liquor is heated and is very uickly thereafter absorbed by the textile material. Thus. prolonged heating andformation of scum is avoided. Moreover, the temperature of the liquor is maintained substantially constant and is prevented from falling undesirably low.

This control of aqueous liquor supplyis accomplished through a liquor pr'eheater arrangement comprising a :supply tank 47, a small capacity heating tank 48 and connecting pipes 49. 50 and 51. An electrically controlled feed valve 52 is positioned on conduit or pipe 49. Liquor admitted by the control valve 52 and also present in the lines 49, 50 and 51 is circulated through the apparatus by the pump 53. As the level of the liquor 46 in the dye box 44 drops, control valve 52, in 'a manner to be described more fully hereinafter, is opened in order to allow entry of more liquor into the system to pass to the heating unit 48 and thence to the dye box 44.

The liquor in the heating tank 48 isheated by a coil of tubing 54 supplied with steam from a thermostatically controlled steam valve 55, the thermostat having control contacts 56 in the heat exchanger 48. As shown, the contacts 56 are positioned on the discharge side of the heating tank 48.

The aqueous cloth. treating liquor in the supply tank 47 is maintained at a relatively low temperature of preferably 25" to 30 C. Through the action of the control. valve 52 and the heating means 48, the liquor is only heated just prior to its passage intothe dye box 44 up to .a temperature of about 80 C. Thus, the liquor is at this elevated temperature for only a short period before .it is absorbed by the cloth 1 passing therethrough.

Theliquor feed control valve 52, mentioned above,

The dye liquor layer 46 may be maintained at any desired average depth, for example 12 inch, and with a cloth width of, for example, 50 inches, only a relatively small quantity of about /2 to 1 gallon of dye liquor is in use in the dye'box 44 in contrast with the 30 to 60 gallons normally used such as in a dye jig. An adjustable metal rod 57 projects down into the dye box 44. The rod 57 is connectedthrough a relay S8 to an electric battery 59 which in turn is connected to the dye box 44. The elec trical actuation or tripping of the relay 58 operates the liquor feed valve: 52 which'is connected to the relay 58 by leads 60. When the level of the liquor in the dye box 44 rises and contacts the metal -rod 57, the circuit operatesto close the feed valve 52, the rod acting as an electrical conductor, and when the liquor drops down below the end of thezmetal rod 57, the feed valve, in turn, is opened. In this fashion a substantially constant level of liquor 46 is maintained in the dye box 44.

'It is found that the caustic solution of the dye liquor is liable to form froth on the liquor surface and as these froth bubbles act as conductors in the same manner as the liquid-to give a possible false indication of liquor level, a small quantity of turpentine or other suitable liquid, e. g., hydrocarbon, may be floated 'on the surface of the dye liquor 46. This eliminates frothing and causes the relay 58 to be actuated only by the true liquor level.

As the avoidance of any localized overheating of the liquor depends on the rate of the liquor flow, and since the'liquor flow from the tank 48 may be required to cease temporarily, a conduit 61 is provided which connects the dye box 44 with the conduit 50 through the electrically controlled valve 52 and the connecting pipe .49. A circulation valve 62 in the conduit 61 is electrically controlled by the relay 58 which operates to open the valve 62 when the valve 52 is closed and vice versa. In this manner, the liquor flow through the heater 48 is constantly maintained.

As indicated in dotted lines at 63, the cloth 1 may, in addition to passing through the liquor 46, pass through a trough 53 in order to take up aqueous treating liquor. In this case, the level of the liquor in the trough 53 is maintained constant and is supplied from a main supply tank (not shown). The trough 53 may be located to receive the cloth prior to the heating on the .cylinders 29, if desired. As an example of relative values in the operation of the process, with the metal bath at 90 to 95 C. and with a treating liquor 46 floating thereon at about to C., the cloth '1 should be preheated so that upon entering the treating liquor 46, the cloth temperature is such that the temperature of the combined cloth 1 and treating liquor 46 is not less than 75 C. For example, a textile material 1, having a specific'heat of 0.3, absorbs 130% by weight of treating liquor 46 having a specific heat of 1.0 at 80 C. and should enter the treating liouorat 72 C. if the combined temperature is to be 78.5 C.

It is desirable to maintain the temperature of the molten metal bath at no greater than to C., since at higher temperatures with the aqueous treating solutions, steam may be generated below the surface of the molten metal and passed up through the metal bath and interferewith the even application of the dyeing liquor and cause Streaky dyeing. Furthermore, it has been discovered that if the molten metal treating process is operated so that the cloth upon .as it emerges from the molten metal bath. When this transpires, unsatisfactory results are obtained.

The cloth upon emerging from the molten metal bath. passes through a box 54 which is open at both ends and which projects into the molten metal bath. The box 64 contains an aqueous liquor 65 which floats on the surface 45 of the molten metal. The aqueous liquor 65is supplied to the box 64 by gravity from a tank 66 heated by the steam pipes 67 to which steam is introduced in controlled quantities through a valve 68 regulated by a thermostat having its terminals 69 projecting into tank 66. The solution in the box 64 '13 is maintained at constant leve l by overflowing on to the surface 45 of the molten metal. As in the case :D heapn ratus rShOWIl in Figured, he moltenzm l treating b th 4 of he-amaratusof'Figurc. consists of two side members 13 and 14 .;and ,a vertical center :partition .17. Along h e -verticail.-:sides :aWiihiu recesses, there :are .eloca ed heating elements such as the steam pipes 70 which in the form of apparatus of Figure 11 are fed through the pipe 71 which is controlled by the valve 72 through the thermostat control 73 which projects down into the molten metal bath below the surface 45 The following further illustrative examples of actual operations conducted in accordance with the procedures of the present invention are given in order to provide a further understanding of the details thereof.

Example M1 This exampl illu trates th r t .dyciii i ot n fabric. In addition, it illustrates also.the Nat dyeing of viscose and linen fabrics.

Cot-ton fabric which has been :dried after --scouning and blcaching is passed 'fIOmZt bll1l(-*F6lljih6f60f on to heating cylinders where the fabric gleaves alspace of :about 7 feet from 'the last *heating cylinder into -a. dye bath 8 inches deep which floats on the surface of molten m al alloy l ontained in .a U-sh ped yess l w th-le ,5 ;feet deep. The fabric on entering ythe dye; liquor has zaqtemperature of 7 'C- T e-m al all Qutai cd in th -shaped vessel h s a e te ti acemuasitia .zof approximately 13.3% tin, 26.7% lead, 50% .bismllth,.an l 1.8% ca mi man possess s -lmeltingro n vof abou -C.

The dye liquor indicated as .floatingon ,themolten metal surface. i made up and sto ed a r om tem- ,pcra ure (20 .C.) andris pumped :to-rhedye bathvanr he :surfa .of the molt n me al-th ou a dyeiprcheat r which heats the ye l quor t 7.5 Q. lw'ith aa few minutes of. ts abs rption byethe co t r'fabri The dye liquor employed has the following -comrpositi n: 50 gins l- =of-the a dycstuff '-d.ic lam' .2e nthraquinone .a ridone (Col r i'l da 1116 .as .sold commercially y L 1 4d, as Qal domrc Wiolc 2 R. N. S. 2 gms./l. fCalsoline oil supplied by I. C. I. Ltd.

'20 gms./l. sodium hydroxide 30 gms./l. sodium hyrosulphite -l=5 .gms./l. glucose The m l en metal-is maintained in theatri l-i115 dea .at a temper t re of .C- by aut matical y .c. nt o heaters. Likewise the supply of the dye li quor to the surf ce of h -m al .andtth emperai rc thctacf ar automatically controlled.

The fabric is passed at azspeedroffimyards perminute I The-'sfabric emerges I-from the unolten :metal into a percent aqueous solutionofiGlauberis-ssaltwhich floats on th vsurf ce f .th m lten m al tatth e it side of the .U haped vessel Th -.iab. i eme n from t Glaubers salt bath is rinsed,.0XidiZQC and .sQaPQd in known manner using the .conventioua QPsn W dfihs aP- ing range.

The resultant cotton fabric is colored a uniform reddish violet shade ofcxcellent 'fastness.

Operating in similar fashion wiscose and "linen fabrics are dyed to give products of reddish violet shade of excellent uniformity throughout the entire surface thereof and of good light fastness.

xample vI/i'l T s-e ample illu trates fli va yeing ql rsutt ni ca u ion f ric- Cotton-viscose fabric which has beenscoured, Qleacheil and dried is dyed using .-a process-as, described in Examp 1, vbut t t fql bwius'fiyc iq 50 gmsj'l. of the -vat dyestufi, trichloro-N-d'ihydroiiirliz aaath aqui eaeaziue -.:=.(G9 Index .1 1 at supplied by I. C. I. Ldt. as Caledon Blue R. Q. S.

. crawl-of asulphate ia y a id s e et ing n .dis-

r ainaa cnt-such as Alcopcl T l y A i C l o s Example VIII This example illustrates the vat dyeing of linen fabric using a r-call d pigm nt padding te hnique- Linen fabric which has been scoured and bleached is impregnated using a suspension of vat 'dyestufi in a twofibow lpadding ,mangleji-n'known manner. "The dye suspension contains:

10 grns./l. Calsoline oil The impregnated fabric is squeezed to leave percento'f liquor in the fabric and is dried in a hot air drying macliine.

The dyest uff thefabric is fixed thereon by passing through the molten .metal machine in .the manner .described-in Example I, but instead of the dye liquor of Example VI, a developing liquor of the-following composition is introduced upon the surface of the molten meta b t and the impre ated fabric pa s d e th o h:

20 grns./l. sodium hydroxide "30 gins/l. :sodiurnxhydrosulphite 2 gms./l. of a sulphonated fatty acid ester wetting agent 15 gms./l. glucose.

':'llhe:'-;fabric is passedzthroug'h the machineat 6.0 yards per minute. The resulting fabric after further oxidation and-scraping .is.;co lored a-'fast full green shade which is uniformmin depthiatndsappearance.throughout the entire length of the 'fabric.

Exampl .1 X

llhisdexample, illustrates .the .dye'ing of cotton-fabrics with sulphur'dyes. "ltalso illustrates the dyeing of viscose and-linen-fabrics with the same type of dye.

Cotton fabric ofthe .pile type having a design woven into esthe pi-le, such as rfabric'iuscd for drapery material, which has been scoured, bleached and dried, is treated according :to ztheniethod; described in Example V1, with the exception that the following dye liquor is employed:

The cotton fabric is -5fed through theapparatus at a speed of 50 yards per minute and after oxidation and rinsing of the fabric, .a product haying a deep navy blue shade is obtained. .-In=.s'imilar fashion dry, scoured, and bleached viscose and linen fabrics are dyedzwith comparableresults.

Example X This example illustrates the dyeing of -Ql;t0n fabric with direct cotton .dyes. italso z-il-lustrates thc dyeing of viscose and linen fabrics with the same type of .dye.

Cotton pile toweling which has been .dr-ied .a ftcr scouring and bleaching, is treatedin the apparjatus as, described in Example VI. The fabric is .not gprcheated before passing into the dye bath and the dye liquor is made up "and stored 'at'"'80 C. Before introduction on *tothe surface of the molten metal bath, -the dye liquor is preheated -'to -a-temperature o'f l-OW C. The

rlrglterci2 metal bath is maintained at a temperature of Example The dye liquor used has the following composition:

5 gms./l. of direct cotton azo dye, Chlorantine Fast 5 Blue 4 GL such as sold by Clayton Aniline Company of Manchester, England. This dye has the following formula:

SOaNa This example illustrates the dyeing of wool fabric with acid dyes. It also illustrates the dyeing of woolunion and natural silk fabrics with acid dyes.

Wool suiting material is preheated to a temperature of 95 C. by passage through a hot air drying machine 2 gms./l. of sulphated secondary fatty alcohol and then passed into the dye apparatus as described in gms./l. Glaubers salt. Example VI.

In the apparatus a dye liquor having the following The fabric is passed through the apparatus at a speed composition is employed:

of 40 yards per minute. Upon emerging from the salt bath at the exit end of the apparatus, the cloth lS rinsed 5 g ns/l, of wool dyestuff, the sodium salt of p-sulphoto yield a product having a uniform medium blue color. benzene-azo-beta-naphthol (C 1 Index 151) such as Operating in similar fashion, viscose and llnen fabrics O 11 supplied by L, B, l-lolliday & Company are dyed in identical fashion to give comparable results. 10 gmsjl, f l h t d secondary fatty l h l wetting Example XI agent This example illustrates the dyeing of spun viscose The dye liquor made up and Stored at fabric with direct d es. It also illustrates the dyeing and supplied to the Surfaces of molt metal bath of cuprammonium g fabrics with Such dyes at a temperature of 100 C. while the molten metal Dry scoured viscose fabric is dyed using the procedure bath, maintained at a temperature of The described in Example X, but with a dye liquor of the fabnc 15 Pased f l the appara tus i a Speed of 20 following composition: yards per mlnute giving an immersion time of 0.66 sec- 0nd in the d e bath and 10 seconds for assa e throu l0 gms./l. of direct cotton dyestuff, the SOdllllTl salt of the molten 3 bath At the exit g ig P P 9 3Z0 5 l' bath consisting of a 1% aqueous solution of acetic acid amlflo-1-I1aPhth01-3fimghonlc-acld (C010r lndfx maintained at 95 C. is floated on the molten metal bath. Sold y as Chlorazol Fast Red K Following exit from the acetic acid bath, the fabric 2 g 0f sulphated secolldal'y fatty alcohol Wetting is rinsed in hot water continuously in known manner agent 40 and then dried. Cloth uniformly dyed an orange color 10 gms./l. sodlum chloride i obtained The fabric after rinsing following the dyeing treatment h Same P 9 is j p using Wool-union is uniformly red throughout fabrlc and natural silk fabric with comparable results In another case, cuprarnmoniurn rayon fabric is dyed 111 color: Shade and ulllform Coverageby the same procedure and with comparable results. Example XV Example XII Example XIV is repeated substituting the following This example illustrates the dyeing of Wool fabric with dye q vat dyes. It also lllustrates the dyelng of wool-union 5 of acid dye, the sodium salt of 4 p sulphoben fabric and natural silk fabric with vat dyes. Zane azo 1 0 m dichloro p sulphophenyl 3 HeaYy 1 mapped f, Much has been scoured methyl-S-hydroxy pyrazol (Color Index 639) such as n dl'led 1S Priiheated to by Passage througha Xylene Light Yellow 26 supplied by Sandoz Chemradiant heat unit after WlllCll 1t 1s passed through a dye ica] C0mpany bath floating upon a molten metal bath such as described in Example VI. A dye liquor having the folg sulphated secondary fatty alcohol wet lowing composition is used: 10 1 formic acid (80%) 30 gms./l. of Caledon Red B. N. S. sold by I. C. I. The fabrics, following hot watm. washing and L d ing, possess a uniform yellow color.

Example XVI t 5 gms./l. of sulphonated oil wetting agent 4 gms./l. sodium hydroxide g gggg l This examples illustrates the dyeing of wool fabrics, 0 wool-unlou fabrics and natural silk fabric with soluble The fabric is passed through the mach ne at a rate acetate dyes 0f 40 y l' P and after developlng, OXldlZmg The process described in Example XIV is repeated and soaping of the fabric, a cloth dyed a fast red color using h f ll i dye liquor; is obtained. No apparent damage to the wool fabric due to contact with hot strong alkali can be observed. 5 gmS-/ of Soluble acetate y W11 as Solac t fast In similar fashion, natural silk fabric is dyed a fast Orange, 2 as Sold y 1 wh ch 1s a red olor, water-soluble dlsazo dye 10 gms./l. of sulphated fatty alcohol wetting agent Th d r E 1 XII e eated usin d e 10 acid 6 proce ure 0 xampe IS I p g y An orange colored fabric of uniform shade is obliquor of the following composition:

tamed following hot water rinsing and drying, upon 100 gms./l. of the vat dye dlmethoxy-dibenzanthrone exit f the treating apparatus (Color Index 1101) such as sold by I. C. I. Ltd. as Caledon Jade Green R. N. S. Example XVII 5 gms./l. sulphonated oil wetting agent This example illustrates the d yemg of cotton, viscose g g 855? g g and: linen fibrlizcs with bilSlC dyeszz1 d k otton uc materia is mor ante in nown man- %8 'fl' f hydrosulphlte ner with tannic acid. After drying of the fabric, it is g moss heated to 75 C. by passing over steam heated cylin- Fabric speed with both the wool fabric and natural ders and is then passed into apparatus such as described silk fabric is 40 yards per minute and in each case in Example VI through dye liquor floating on the surthe fabric is dyed a uniform green color. face of the-molten metalbath maintained at a tem- Example XIII and rinsed, following once-p95 perature of 9 6.- The dye liquor possmses the followin composition:

5 :g'ms/l. of the basic dye, tetramethyl-diamino-diphenaz'thioniurn chloride Color Index 922) such as Methylene Blue 2B supplied by I. c. I. Ltd.

6d. per liter methylated spirits 'The dye liquor is made up by pasting the dry dyestuff With the methylated spirit and is then diluted to required volume with cold water. The dye liquor is stored cold and just prior to floating upon the surface of the molten metal bath, it is heated to 75 C. by passing through a preheater.

The fabric is passed through the dyeing apparatus at 30 yards per minute and leaves the molten metal bath through a water bath of 95 C. floating on the exit side of the molten metal. The fabric after drying has a uniform blue color.

The identical procedure is followed with viscose and linen fabrics with comparable results.

Example XVIII The example illustrates the dyeing of cellulose acetaterayon and polyester (Teryl'ene) fabrics with dispersed acetate dyes.

Dry, scoured cellulose acetate rayon fabric is passed from a bulk roll through a hot air dryer where it is heated to a temperature of 75" C. and from there into a dye bath floating on the surface of a molten metal bath in apparatus such as described in Example VI. The dye liquor through which the cloth passes possesses the following composition:

10 gms./l. of acetatedye ffDuran'ol Red X3 B 300 powder as sold by I. C. I. Ltd. which is an aminoan'thraquinone derivative 5 gms./l. soap flakes The dye liquor is made up and stored at 75 C. and is pumped to the dye bath container on to the surface of the molten metal at this temperature. The fabric is passed through the dye and through the molten metal which is maintained at a temperature of 99 C at the rate of 30 yards per minute.

It leaves the molten metal through a bath of hot water floating upon the The fabric is passed through the dye ap aratus at a speed of 30 yards per p minute and upon being washed the dyeing: operation, possesses a good yellow shade.

Example This an example of the u e of the present invention for dyeing of nylon with acid dyes.

Dry, scoured nylon fabric is" dyed according to the method described in Example XVIII using the following d'ye liquor:

10 gms./ 1. of the acid dye, the sodium salt of benzeneazo-beta-naphthol-6, S-disulphonic acid (Color Index 252) such as Croceine Scarlet 3 B" sold by I. C. I. Ltd. 10 gms./1. formic acid (80%) 1 gm./1.. sulphated fatty secondaryalcohol wetting agent The dye liquor is made up and stored at 95 C. and is pumped to the dye liquor chamber at the surface of the molten metal bath at this i'r'llp'latlile. The nylon fabric is passed through the apparatus atthe speed of yards per minute giving an: immersion time of 0.66 second :1n the dyeliquor' and l0'seconds in the molten metal.

Uponemerging from the apparatus, the nylon fabric is rinsed. and. dried. A material which-is uniformly colored scarlet throughoutthe entire lengththereofis obtained.

18 Example XXI This example illustrates the dyeing of both nylon and orlon fabrics by vat dyes. I

Nylon fabric which has been scoured and then dried is processed continuously by the procedure described in Example I using, however, the following dye liquor:

30 gms./ 1 of thioindigoid vat dyestuff such as Durindone Pink F. F. S. as sold by I. C. I. Ltd. which is 6.6- dichloro 4,4' dimethylthioindigo.

2 gins/1. sulphonated oil wetting agent 15 gins/1 sodium hydroxide v 15 gms./1 sodium hydrosulphite 15 gms./1 glucose The cloth is processed at a rate of 20 yards per minute and following the usual, oxidation, soap'ing and rinsing steps, nylon fabric having the expected pink color is obtained. I

In another case anon fabric is processed in an identical way with comparable results.

Modifications The type of metal used in the essential metal bathv is important to the success of the present invention. There are a number of usable metals but those most, desirable have a melting point between 60 and 100 C. and especially between 60 and 80 C. The most satisfactory metals of this type for the purpose are lead and bismuthcontaining eutectic alloys such as Woods alloy, Roses alloy and the like; A particularlydesirable specific alloy is described in the examples.

Many types of aqueous liquors may be used incarrying out thenew processes. Although better results are obtained with some formulations of the liquors than with others, wide variations in the concentratio s, types and combinations of ingredients present in the treating mixtures may be used. Obviously, the aqueous liquors should not include ingredients which are reactive, in the concentrations used, with the metals contained in the bath, for example, heavy metals such as lead, bismuth, tin, cadmium or the like.

Dyestufl solutions or suspensions comprise the aqueous liquors, however, most useful in the new operations. The usable dyestufis include all those known to be useful in dyeingorganic filaments. This includes vat, sulphur, direct, acid, and all other generaltypes of dyes. As a matter of fact, one of the primary advantages of the present invention is its ability to' be used with so many different classes of dyestufisf, with equally fine results'. As those skilled in the art know, vat dyestuffs are generally grouped into three separate classes depending upon the particular temperature range that has been required to be used in the past with the dyestuffs in, dyeing. Such groupingstare substantially nullified, however, by the present invention because virtually all vat dyes may be successfully used in the new operations at one and the same temperature range, e. g}, to C.

Numerous specific dyes are mentioned in the foregoing examples and there is no need to list more here because of the extreme'yariety which may be employed.

When dyeing liquors are employed, they-may include supplemental ingredients as is well u known in the art. These include wetting agents, emulsifying agents, dispersing agents, inorganic and organic salts and acids, soaps, syndets, gums, colloids, corrosioninhibitors, organic solvents, developing agents and the like. Specific substances are given in the foregoing examples and since there are so many more which can be used and will be apparent to those skilled in the art, a further detailed list here is unnecessary. L

Other reagents which may be included in the aqueous treating liquors, either alone or in mixture with themselves or any of the above, include moth-proofing agents, crease-proofing agents, scouring agents, sizes, waterrepellant producing agentsfand' the like. These are all well known in the art and they are all generally applicable to the new operations.

Concentrationsand ratios of the reagents in the aque- (His liquor andnot critical. These amounts" generally employed with prior known procedures of comparable amounts as required by the particular textile material being treated maybeused.- The foregoing examples illustrate this'feature of'the' invention sufficiently to enable anyone skilled inthe art to adapt the new operations to any special case.

The depth or other dimensions of the aqueous treating liquor bath are not critical and may be varied. Since all or a section of the aqueous liquor is: floated upon the surface of the molten metal bath, a certain practical limit is imposed upon the aqueous bath depth clue to the hydrostatic head which may be supported, but this always has been found sufiicient in actual operation. Usable depths of aqueous liquor floating above the molten metal bath may be from about 1 inch to about five feet, although shorter or much longer depths may be used. The width and length of the aqueous baths will be varied to accommodate the size of the textile material under treatment. It is desirable to make the aqueous bath, however, as small as possible, so that a minimum of treating liquor will be required. In this regard, a depth of 8 to 12 inches, a width of one inch and a length just slightly longer than the width of the fabric to be treated are preferred dimensions. This allows for saving in material, control in uniformity of temperature and strength as the operations progress, and permits faster changeover.

In those operations where an aqueous treating liquor containing a hydrosulphite is used, the liquors preferably include an anti-oxidant. This helps to inhibit formation of sludge on the surface of the metal bath. Reducing sugars, e. g., glucose, are preferred, but other suitable ageits include aldehydes, e. g., benzaldehyde, and tannic acl The function of the antioxidant is to inhibit the tendency of the hydrosulphite to decompose to form products which attack the metal of the bath. Very small amounts of sutiable antioxidant will accomplish this purpose and the minimum quantity necessary can be determined by simple observation. Since the deleterious decomposition is a function of many factors, e. g., proportion of hydrosulphite, temperature of operation and the time during which the hydrosulphite is maintained at the elevated temperature, no precise minimum proportion of antioxidant can be presented. Since suitable antioxidants are quite mild, they do not interfere with the solubilization of any ordinary vat or sulphur dyestuff even when the antioxidant is employed in quantities as large as the quantity of hydrosulphite employed. Such large quantities are far more than required for any conceivable dyeing or dye reducing operation.

Temperature of the aqueous bath during treatment of the textile material is important. When the aqueous liquor is floating upon the metal bath, it should be above the melting point of the metal and below its own boiling point, and preferably, between 80 and 100 C. Where a temperature sensitive liquor is employed, such as is the case of various dye liquors which deteriorate upon standing at elevated temperatures, the liquor is best heated just prior to being floated upon the metal bath. Thus, the liquor may be stored at room temperature (about C.) and then heated in suitable fashmg: the way to the bath container to about 80'? to The temperature of the molten metal bath is also important. Obviously, it must be above the metal melting point. Also. it should be below the temperature at which ebullition of the aqueous liquor takes place as the cloth passes therethrough. This may be as hi h as about 103 to 105 C., or higher, due to the high pressures in the metal bath and the cooling effect of the aqueous liquor and the cloth upon the upper re ion of the molten metal bath at the entrance end. Preferably. the emperature of the metal bath is about 80 to about 100 C.

The process is operated in best fashion when an aqueous liquor also floats upon the exit surface of the metal bath. It has been found that the presence of an aqueous layer where the textile material emerges from the molten metal bath greatly reduces the tendency of the textile material to pick up particles of the molten metal. This has been discovered to greatly improve the results apparently due to several reasons. First, it insures that the cloth as it leaves the metal bath will remain wet with aqueous liquor. This appears to keep metal from the bath from being picked up and carried along with the cloth and to prevent streaks, blotches or the like, from forming on the cloth. Also, the exit floating liquor reduces scum formation on the metal bath, and accordingly, the textile material does not leave the molten metal bath with particles of scum clinging thereto.

The nature and composition of the exit floating bath is not critical. Generally, it is a salt solution, e. g., Glaubers salt, sodium chloride, etc., but it may be any other desired aqueous liquor of a character adapted to assist or complete the treatment being carried out in the transit through the metal bath, or of a character calculated to assist any subsequent treatment. Clearly, the exit liquor could also be neutral, for example, plain water. The same comments regarding reagent concentrations, ratios, temperature and the like made relative to the inlet floating aqueous bath apply to the exit bath.

It has been discovered that when dyeing with vat or sulphur dyestuffs, the exit liquor quickly becomes contaminated with caustic soda and hydrosulphite. The tendency of this alkaline exit liquor is to strip some of the dye already applied to the material, thereby giving a streaky effect. To overcome this particular defect, the exit liquor may consist of a strong solution of common salt or Glauber salt, fresh solution being added as necessary to maintain the exit liquor in a condition so that it does not substantially afiect the previously applied dyestuff.

Further. when dyeing with vat or sulphur dyestuffs, the exit liquor should not be made acidic since under acid conditions, hydrosulphite decomposition products attack the metal to form a sludge. The formation of sludge where the textile material emerges from the molten metal bath causes adherence of sludge and metal to the textile material and thereby causes faulty treatment, for example, patchy dyeing, and loss of metal.

The floating liquor at the exit side should be maintained at a temperature in excess of the melting point of the metal. The depth of the liquor is not a critical factor and 12 inches has been found to be satisfactory. Squeezing rollers may be used to limit the amount of liquor carried away from the floating layer at the exit side by the textile material.

Another feature of the new processes which has been found to provide for very excellent results, is the preheating of the cloth prior to contact with the floating inlet liquor. This has been discovered to provide, for example, excellent uniformity of coloration in dyeing with the new processes.

The exact temperature at which the cloth is preheated before being passed into the aqueous liquor bath is not critical. The upper limit is generally determined by the cloth itself and the temperature at which it may be safely heated without deterioration. For ordinary purposes, 120 C. can be regarded as a practical upper limit. In the preferred embodiments, the cloth is heated to between 80 and 100 C. The desired condition is to have the cloth preheated to such a temperature that upon entry into the aqueous treating liquor its temperature is such that the combination of specific heats of the cl th and of the aqueous treating liquor and any thermal effect arising from their mixing, will cause the cloth and the aqueous liquor with which it is im regnated to have a temperature not less than about C. A specific example of temperature values and specific heats has been given in the previous discussion.

As has been indicated before, it has been discovered that the presence of substantial amounts of moisture in the textile material is essential during passage throu h the molten metal bath if the cloth is to emerge properly treated. Of course, the percentage of aqueous treating liquor present in the cloth during passage through the molten metal may be varied and will depend to a certain extent upon the particular treatin solution and upon the nature of the textile material. However, as a general rule and in those cases where the metal temperature is l00 C. or below, at least about percent by weight of moisture is necessary in the textile material for satisfactory results. In those cases where the metal temperature may be maintained at over C., less moisture can be tolerated as a minimum owing to the ebullition that takes place as the textile material passes through the upper region of the molten metal bath or the exit thereof and the consequent resistance to metal absorption. Satisfactory results have been obtained with 60% of moisture by weight under these conditions. However, when operating at temperatures above 100 C., care must be taken to insure that there is insufficient ebullition of moisture vapor as to result in the cloth leaving the molten metal bath without any or with only a very low quantity of moisture therein, e. g., about 40% or less. The upper aqua-ace 21 limit of moisture content is not. critical and-in practice is primarily governed by the squeezing action .ofthe molten metal bath. 'It may be. as. highastlotflrwith certain textile materials.

One of the very important features of thepresent invention is the very high rateof dye transferred which enables textile material to be processed at very highrates of speed. The exact speed that the textile material is passed through the treating liquor and-metalbaths will depend both upon the natureof the textil material, as well as the composition and nature ofthe aqueous-treating liquor. In the case of dyeingeperations, the speed will vary slightly with different dyes andalso with different depths of desired shade, although in all cases the difference in speed will only amount to .a fewseconds. There is actually no critical lower limit. onspeed ottextile passage and it could be actually onlya; fraction of a not a minute. Howeven'in commercial operations, it is de sirable to run as rapidly as possible,,-and it has been found that with these new: pr cedures, amaxirnum speed of 120 yards per minute or over car be obtained, Actual ly this upper limit has. been found to hetixed; hymechanical aspects of the process, and .perfectlysatistaetory dyeings have been obtained even at, these maximum speeds.

Such speeds show how rapidly dye. t-r-ansier'and fixation are completedby these ne'wprocedures. As an example, if the passage through, themolten-metal is 1.0 feet and through the dye bath is. 8 inches, aspeed of-BO yards per minute gives an immersion of 0.44 second in the dye bath and 6.6 seconds in the molten metal, At 120 yards per minute. the cloth remains 0.1l. second in-the dyebath and 1.67 seconds in the metal. These short times, however, are. sufficient forthe dyeing to-be completed and this, of course, constitutes, one of the unusual and unpredictable aspects of the new procedures. .In actual practice, variation of cloth speed has been found to have little or no. effect on either the depth of shade or quality of dyeing, providing the time is suflicient within the baths to give the required fixation. If cloth is run at 100 yards. per minute with complete fixation, slowing down to 30 yards per minute or varying the speed as often as desired, has substantially no effect on the shade. Those skilled in the art will, therefore, recognize the commercial im ortance. of this, Si C it cit-i ables substantially unskilled workers. .to operate the equipment and still obtain satisfactory results.

As will be realized, if depth of shade or the like is desired to be varied, this will be accomplished by changing the composition of the, dye bath or aqueous treating liquor.

As mentioned before, one big problem which has always confronted the dyeing industry has been the ability to transfer tests or experimental runs from the small scale over to a commercial scale. This problem does not existwith these new procedures and this constit tes a t emendous advantage therefor. Thus, by using a small scale model of the new apparatus of this invention, test runs. can be-made. and the data obtained therefrom can be carried over without any substantial change to the commercial operations. to obtain identical results in dyeing-and qualit a One final feature of the new procedures is the-ease with which the apparatus maybe. switched from one treating or dye liquor to another. Thus, at the end of.

any particular dyeing, all that'needs to be. done is to Pump out h y qu r m nin i the sy t m. r move the exit treating liquor and circulate a' cleaning solution through the. system. A suitable cleaning solution is a hot solution of caustic and hydrosulphite. After this cleaning liquor is removed, the. new dye liquor and exit liquor are pumped in, and dyeing with the second shade commences immediately. In actual runs, it has been'found that a complete change can be accomplished in as short a time as fijve minutes. This compares most favorably with the three'to four hours which have been required earlier dyeing methods and apparatus,

been followed by specific examplesof actual operaconsisting of dyeing and dye reducing liquors and wherein the textile material is penetrable by said aqueous liquor, thesteps which comprise continuously passing said textile material, without first passing the same through a bath of molten metal whereby the textile material. will be free of metal penetrations and adhesions,

through a fluid layer of said aqueous liquor floating on a bath of molten metal ,-whi.chqdoes not chemically react with said textile material and the. aqueous liquor thereon, passing the textile material. directly from the aqueous liquor into said moltenmetal bath without exposure to the atmosphere, and continuously passing the treated textile material downwardly to a substantial depth, later- .ally and upwardly in a continuous molten metal path,

whereby aqueous liquor taken up by the textile material as the latter travels through the. floating layer may be subjected during its passage through said path of molten metal. to chemical reaction, penetration and uniform squeezing due to the temperature and the pressureof the molten metal, the melting point of the metal of. the molten metal bath being not more than about 100 C. and the molten metal having atemperature below'that at which substantialebullition of the aqueous liquor occurs.

2. In the process of claim 1, providing a a small volume of the aqueous liquor, floating the small volume of aqueous liquor on 'top of the molten metal, and substantially continuously replenishing the aqueous liquor as it is absorbed by the textile material.

3. A process as recited in claim 1 in which the continuous molten metal path is longer than the Path of itravel of the said textile material through the said floating iquor.

4. In the art of dyeing textile material in continuous length with an aqueous. dye liquor and wherein the textile material is penetrable by said aqueous liquor, the

' steps which comprise continuously passing said textile material, without first passing the same through a bath of molten metal whereby the textile material will. be free of metal penetrations and adhesions, through a fluid layer of said aqueous liquor floating on a bath of molten metal which does-not chemically react with said textile material and the aqueous dye thereon, passing the textile material directly from the aqueous liquor into said molten metal bath without exposure. to the atmosphere, and continuously passing the treated textile material downwardly to a substantial depth, laterally and upwardly in a continuous molten metal path. whereby aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passage through/said bath of molten metal to chemical reaction, penetration and uniform squeezing due to the temperature and the. pressure-of the molten metal, the melting point of the metal of the. molten metal bath being not more than about C. and the; molten metal having a temperature below that at which substantial ebullition of the aqueous liquor occurs.

5. In the process of claim 4., floating a plurality of different aqueous dye liquors at separate locations on the surface of the molten metal, and passing separate. yarns simultaneously through such separate. locations, whereby the yarns. are differently dyed simultaneously.

6. A, process as recited in claim 4 in which the dye is selected from the group consisting. of vat dyesand sulfur dyes. v v

7. In the art of dyeing textile material in continuous length with an aqueous dye liquor andwherein the textile material ispenetrable by said aqueous liquor, the steps which comprise continuously passing said textile materials ith tfi r s i s h sein th u h. a bath of molten metal whereby the textile material will be free of metal penetrations and adhesions, through a fluid layer of said aqueous liquor floating on a bath of molten metal whichdoes not chemically react with said textile material and the aqueous dye thereon, passing the textile material directly from the aqueous liquor into said molten metal bath without exposure to the atmosphere, and continuously passing the treated textile material downwardly to a substantial depth and upwardly in a continuous molten metal path which is substantially vertical along the greater part of its length, whereby aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passage through said bath of molten metal to chemical reaction, penetration and uniform squeezing due to the temperature and the pressure of the molten metal, the melting point of the metal of the molten metal bath being not more than about 100 C. and the molten metal having a temperature below that at which substantial ebullition of the aqueous liquor occurs.

8. In the art of dyeing textile material in continuous length with an aqueous dye liquor, said textile material having interstitual voids therein whereby the textile material is penetrable by the said aqueous liquor, the steps which comprise continuously passing said textile material, without first passing the same through a bath of molten metal whereby the textile material will be free of metal penetrations and adhesions, through a fluid layer of s id aqueous liquor floating on a bath of molten metal which does not chemically react with said textile material and the aqueous dye thereon, passing the textile material directly from the aqueous liquor into said molten metal bath without exposure to the atmosphere. and continuously passing the treated textile material downwardly to a substantial depth, laterally and upwardly in a continuous molten metal path, whereby aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passage through said path of molten metal to chemical reaction, penetration and uniform squeezing due to the temperature and the pressure of the molten metal, the melting point of the metal of the molten metal bath being not more than about 100 C. and the molten metal having a temperature below that at which substantial ebullition of the aqueous liquor occurs.

9. In the art of dyeing textile material in continuous length upon which a dyestuff in unreduced form has been padded, said textile material having interstitial voids therein whereby the textile material is penetrable by an aqueous dye reducing liquor, the steps which comprise continuously passing said textile material, without first passing the same through a bath of molten metal whereby the textile material will be free of metal penetrations and adhesions, through a fluid layer of an aqneous dye reducing liquor floating on a bath of molten metal which does not chemically react with said textile material and the aqueous liquor thereon, passing the textile material directly from the aqueous liquor into the said molten metal bath without exposure to the atmosphere, and continuously passing the treated textile material downwardly to a substantial depth. laterally and upwardly in a continuous molten metal path, whereby aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passa e through said path of molten metal to chemical reaction, penetration and uniform squeezing due to the temperature and the pressure of the molten metal, the melting point of the metal of the molten metal bath being not more than about 100 C. and the molten metal having a temperature below that at which substantial ebullition of the aqueous liquor occurs.

10. In the art of dyeing textile material in continuous length with an aqueous liquor containing at least one dye selected from the group consisting of vat and sulfur dyes and mixtures thereof, alkali and reducing agent, said textile material having interstitial voids therein whereby the textile material is penetrable by the said aqueous liquor, the steps which comprise continuously passing said textile material, without first passing the same through a bath of molten metal whereby the textile material will be free of metal penetrations and adhesions, through a layer of said aqueous liquor floating on a bath of molten metal which does not chemically react with said textile material and the aqueous liquor thereon, passing the textile material directly from the aqueous liquor into said molten metal bath without exposure to the atmosphere, and continuously passing the treated textile material downwardly to a substantial depth, laterally and upwardly in a continuous molten metal path, whereby aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passage through said path of molten metal to chemical reaction, penetration and uniform squeezing due to the temperature and the pressure of the molten metal, the melting point of the metal of the molten metal bath being not more than about C. and the molten metal having a temperature above 60 C. and below that at which substantial ebullition of the aqueous liquor occurs.

11. In the process of claim 10, providing a small volume of the aqueous liquor, floating the small volume of liquor on top of the molten metal, and substantially continuously replenishing the aqueous liquor as it is absorbed by the textile material.

12. In the art of dyeing textile material in continuous length upon which has been padded at least one dye selected from the group consisting of vat and sulfur dyes and mixtures thereof, said textile material having interstitial voids therein whereby the textile material is penetrable by an aqueous liquor, developing said dye by the steps which comprise continuously passing said textile material, without first passing the same through a bath of molten metal whereby the textile material will be free of metal penetrations and adhesions, through an aqueous layer of liquor containing alkali and reducing agent floating on a bath of molten metal which does not chemically react with said textile material and the aqueous liquor thereon, passing the textile material directly from the aqueous liquor into said molten metal bath without exposure to the atmos here, and continuously passing the treated textile material downwardly to a substantial depth and upwardly in a continuous molten metal path, whereby the said aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passage through said path of molten metal to chemical reaction, penetration and uniform squeezing due to the temperature and the pressure of the molten metal, the melting point of the metal of the molten metal bath being not more than about 100 C. and the molten metal having a temperature above 60 C. and below that at which substantial ebullition of the aqueous liquor occurs.

13. In the process of claim 12, providing a small volume of the aqueous liquor, floating the small volume of liquor on top of the molten metal, and substantially continuously replenishing the aqueous liquor as it is absorbed by the textile material.

14. In the art of treating textile material in continuous length with an aqueous liquor selected from the group consisting of dyeing and dye reducing liquors and wherein the textile material is penetrable by said aqueous liquor, the steps which comprise continuously passing said textile material. without first passing the same through a bath of molten metal whereby the textile material will be free of metal penetrations and adhesions, through a fluid layer of said aqueous liquor floating on a bath of mol en metal which does not chemically react with said textile material and the a ueous liquor thereon, feeding the aqueous liquor to said floating layer, preheating said aqueous liquor as it is fed to the layer whereby said aqueous liquor is introduced to said floating layer at elevated temperature, passing the textile material directly from the aqueous liquor into said molten metal bath without exposure to the atmosphere, and continuously passing the treated textile material downwardly to a substantial depth, laterally and upwardly in a continuous molten metal path, whereby aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passage through said path of molten metal to chemical reaction, penetration anduniform squeezing due to the temperature and the pressure of the molten metal, the melting point of the metal of the molten metal bath being not more than about 100 C. and the molten metal having a temperature below that atwhich substantial ebullition of the aqueous liquor occurs.

15. A process as recited in claim 14 in which the aqueous liquor is supplied to the said floating aqueous layer at substantially the same rate at which the aqueous liquor is taken up by the material passing therethrough whereby said aqueous layer may be maintained at relatively small constant volume and" at substaht-ialh constant temperatureandstrengthl i 16. A process as recited in claim liin-which-the" aqueous liquor employed to replenish the aqueous liquor in'the said layer is heated from a temperature of'about 25 to 30 C. to about 80 C. just prior to its addition to the layer.

17. A process as recited in claim 15 in which a portion of the said aqueous liquor floating on the molten metal bath is withdrawn, heated to a temperature of about 80 C., and then recycled for return to the body ofiliquorfrom which it was withdrawn at a sufiicie'nt rateto main tainthe temperature of the floating liquor substantially constant- 18. A process as recited in claim 14in which the said aqueous liquor contains hydrosulphite.-

19. in the art of treating textile material in continuous length with an aqueous liquor selected from the group consisting of dyeing and dye reducing liquors. and" wherein the textile material is penetrable by said aqueous liquor, the steps which comprise continuouslypreheating said textile material and continuously passing said heated I textile. material, without first passing the same through a bath of molten metal whereby the-textile material will be:

free of metal penetrationsiand adhesions, through a'fluid layer of saida'queous liquor floating onabath of molten metal which does not chemically react with said textile material and the aqueous liquor thereon, passing thetextile material directly from the aqueous: liquorinto said molten metal bath without exposure to the atmosphere,- and continuously passing the treated textile material downwardly to a substantial depth, laterally-and up wardly in a continuousmoltenimetal path, whereby aqueousv liquor takenup. by the textile material as the latter travels through the floating layer may be subjected during its passage through said path ofmolten'metal t'o chemical. reaction, penetration and uniform squeezing-due tothe temperature and the pressure oh the molten metal the melting point of the metalof the molten metal bath i being. not more, than. about 100 C: and themoltenmetal ebullition. or the aqueous liquor occurs";

20-. in the art or treating. textilematerial; in continuous the groupmatcriatdirectly from the aqueous, liquor into said molten metalbath without.exposuretotheatmosphere, and continuously passing the. treated textile material downwardly to asuostantial dep.th,..laterally.andiupwardly in: a continuous molten-,metalpatmwhereby aqueous liquor; takens up. by the textile. material as .the latter travels through the. floating layer may be..snbjected through said path ofmolten metal tolchemlcal reaction, penetration and uniform squeezing due to the temperature and: the pressure of the molten point .of .the metal of .themolten :metalz. bath beihgibetween about 60? C.. and about 100.v C.,..said molten metal having a temperature above 60 C. and below that at which substantial ebullition of the aqueous liquor occurs.

21. A .process,,.as.recitedt in claim; 20 which'isaid floatingaqueous layer. contains hydrosulphite: together with an antioxidant to inhibit the formation of sludge on the surface of the molten metal bath.

22. A process as recited in claim 20 in which said floating aqueous layer is maintained in comparatively small volume and is substantially continuously replenished WiLh fresh aqueous liquor as the same is absorbed by said textile material, said replenishing liquor being heated to approximately the temperature of said floating aqueous layer as it is supplied to said layer.

23. A process as recited in claim 20 in which the temperature of the preheated impregnated textile material is above the freezing point of the metal in the molten metal bath when it enters said bath.

24. In the art of treating textile material in continuous during its passage;-

metal, the melting-- having a temperature. belowthat at which substantial--4 length with auaqueeusu uor s'electe'dfrom s nglet-1's" consisting of'dyeing' andzdye' i-educing'li'quors and Whe e' in the textile material is p enetrable by said aqueous liquor, the steps which comprise continuously passing.

said textile material, without first passing the same through a bath of molten metal whereby the textile rnate rial will be free of metal penetrations and adhesiohs;

through a fluid layer of said aqueous liquor floating on a bath of molten metal which does not chemically r'ea'ct with said textile material and the aqueous liquor thereon,- passing the textile'rnaterial directly from the aqueous liquor into said molten metal bath without exposure to the atmosphere, and continuously passing the treatedtextile material downwardly to'a substantial depth, laterallyand upwardly in a continuous molten metalpath, whereby aqueous. liquor taken up by the textile material I as the latter travelsthroughthe floating layer may be subjectedduringits passagethrough said path of molten metal to chemical reaction; .penetration and unifor'nr rial, floating on the surface of said molten metal bath atv the exit side of said molten. metal bath where said textile material, leaves said tendency of said textile material to pick up scum and: particles of: molten metal.

The art or treating: textile: material in continuous length as. recited in. claim 24 in which said aqueous liquor float-ingat the exit side of said metal bathis a solution. of a salt selected'from the group consistinggof sodiumchloride andGl'aubcr salt.-

26.. The; art; of treating textile material in continuous length-as recited in claim 25 inwhich said aqueous treat mg; liquor contains hydrosulphite and said aqueous liquor fioating atv the; exitsideofi said metal bath ismaintained alkaline. v

27.; The art of'treatingtextile material in continuouslength asrecited inclairn 24. in which said. aqueouszliquor floa ing; at: the exit side of. said met-al bath is a solution;

of a lower saturated mono-carbox'yllie acid;

28-. Ln theartoftreating textile material in" continuous length with an aqueous hydrosulphite containing liquorselected from the group,- consisting of dyeingl and dye r.e= ducmg-liquorsand wherein they textile material is penetrablez by said aqueous liquor, the. steps. which; comprise continuously passihgrsaid textile material, without: first passmg tthe same: through; abath of molten metal: whereby.

the textile. materialwilrbe: free-of metal penetrations: and

adhesions, through a: fluid. layer: of said aqueous; liquor" floating'on a: bath of molteirmetal which does not chem-i cally, react with. saidtex tile material and: the: aqueous: liquor thereon, passing the: textile' material directly from the-.aqueoustliquor into saidmoltenwmetal bath without:

exposure to; th'ez atmosphere,.-andr continuouslypassings thertreated textile materiah downwardly to a substantial depth laterally and upwardly in a continuous molten metal-path, whereby-aqueous;liquortaken up. bythe: textile:

material; as;- therlatter travels: through; the floating; layer may; be subjected-during its passage through said path of molten metal tochemicah reaction, penetration and: uniform! squeezingsdue. to; the-temperature and the: pres?- sure of the: molten-:metal; the melting point" of the metal of the molten metal. bath being; not more than about '100- C-kand the-molten -meta1- having: a temperature below that-at whichlsubstantialtebullition ofithe. aqu'e'ou liquor occurs, said aqueous liquor also containing an amount of an antioxidant effective to inhibit the tendency of said hydrosulphite to decompose to form products which attack the metal of the molten metal bath to form a sludge on the surface of the molten metal bath.

29. A process as recited in claim 28 in which said antioxidant is a reducing sugar.

30. Apparatus for the continuous treatment of textile material in continuous length comprising a vessel having side and end Walls and a bottom, a vertical partition member in the vessel between the side walls and spaced from the bottom, the inner faces of the side and end walls and the faces of the partition member together which. isinert to the molten metal and" is not deleterious to the dyeing liquor on. the textile mate" bath to thereby reduce the hydrosulphite. cont-ainingr aces-pee defining a passage of- Ushape whose limbs are substantially wholly vertical and through which the material passes, the inner faces of the side walls being closely spaced along their length from the faces of the partition member, said faces presenting narrow projections to prevent sticking of the said material thereto, said passage forming a container for molten metal and having a substantially vertical downward entry run and a substantially vertical upward exit run, and an open-bottomed trough at the top of the entry run for supporting a layer of treating liquor on the surface of the molten metal so that the material passes through the treating liquor prior to entering the molten metal, and heating means thermally connected with said side walls and said vertical partition member for maintaining the metal which is to be placed within the said container in molten condition.

31. An apparatus as recited in claim 30 in which the said heating means are disposed within said side walls and said vertical partition member.

32. An apparatus as recited in claim 30 in which there is provided means for automatically maintaining the treating liquor at a substantially constant depth in the trough.

33. An apparatus as recited in claim 30 in which molten metal having a melting point not more than about 100 C. fills said U-shaped passage and extends above the bottom of said trough.

34. An apparatus as recited in claim 30 in which metal having a melting point not more than about 100 C. fills said U-shaped passage and extends above the bottom of said trough.

35. In the art of treating textile material in continuous length with an aqueous liquor selected from the group consisting of dyeing and dye reducing liquors and wherein the textile material is penetrable by said aqueous liquor, the steps which comprise continuously heating said textile material to a temperature between 70 C. and 120 C. and continuously passing said heated textile material, without first passing the same through a bath of molten metal whereby the textile material will be free of metal penetrations and adhesions, through a fluid layer of said aqueous liquor floating on a bath of molten metal which does not chemically react with said textile material and the aqueous liquor thereon, said floating aqueous layer being maintained in comparatively small volume and being substantially continuously replenished with fresh aqueous liquor as the same is absorbed by said textile material, said replenishing liquor being heated to approximately the temperature of said floating aqueous layer as it is supplied to said layer, passing the textile material directly from the aqueous liquor into said molten metal bath without exposure to the atmosphere, and continuously passing the treated textile material downwardly to a substantial depth, laterally and upwardly in a continuous molten metal path, whereby aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passage through said path of molten metal to chemical reaction, penetration and uniform squeezing due to the temperature and the pressure of the molten metal, the melting point of the metal of the molten metal bath being between about 60 C. and about 100 C.,.said molten metal having a temperature about 60 C. and below that at which substantial ebullition of the aqueous liquor occurs, and then passing said textile material through an aqueous liquor, which is inert to the molten metal and is not deleterious to the dyeing liquor on the textile material, floating on the surface of said molten metal bath at the exit side of said molten metal bath where said textile material leaves said bath-to thereby reduce the tendency of said textile material to pick up scum and particles of molten metal.

36. In the art of treating textile material in continuous length with an aqueous hydrosulphite contain-- ing liquor selected from the group consisting of dyeing and dye reducing liquors and wherein the textile material is penetrable by said aqueous liquor, the steps which comprise continuously passing said textile material, without first passing the same through a bath of molten metal whereby the textile material will be free of metal penetrations and adhesions, through a fluid layer of said aqueous liquor floating on a bath of molten metal which does not chemically react with said textile material and the aqueous liquor thereon, said floating aqueous layer being maintained in comparatively small volume and being substantially continuously replenished with fresh aqueous liquor as the same is absorbed by said textile material, said replenishing liquor being heated to approximately the temperature of said floating aqueous layer as it is supplied to said layer, passing the textile material directly from the aqueous liquor into said molten metal bath without exposure to the atmosphere, and continuously passing the treated textile material downwardly to a substantial depth, laterally and upwardly in a continuous molten metal path, whereby aqueous liquor taken up by the textile material as the latter travels through the floating layer may be subjected during its passage through said path of molten metal to chemical reaction, penetration and uniform squeezing due to the temperature and the pressure of the molten metal, the melting point of the metal of the molten metal bath being not more than about C. and the molten metal having a temperature below that at which substantial ebullition of the aqueous liquor occurs, said aqueous hydrosulphite containing liquor also containing an amount of an antioxidant eifective to inhibit the tendency of said hydrosulphite to decompose to form products which attack the metal of the molten metal bath to form a sludge on the surface of the molten metal bath, and then passing said textile material through an aqueous liquor, which is inert to the molten metal and is not deleterious to the dyeing liquor on the textile material, floating on the surface of said molten metal bath at the exit side of said molten metal bath where said textile material leaves said bath to thereby reduce the tendency of said textile matrial to pick up scum and particles of molten metal.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 21,402 Crossley et a1 Mar. 19, 1940 1,029,866 Haskell June 18, 1912 1,595,236 Minton Aug. 10, 1926 1,930,601 Townsend Oct. 17, 1933 2,125,364 Waldron Aug. 2, 1938 2,137,256 Waldron Nov. 22, 1938 2,233,101 Kern Feb. 25, 1941 2,375,360 Herrick May 8, 1945 2,387,200 Walter Oct. 16, 1945 2,396,908 Womble Mar. 19, 1946 2,424,857 Scull July 29, 1947 2,458,394 Luboshez Jan. 4, 19.49 2,460,206 Wentz Jan. 25, 1949 FOREIGN PATENTS Number Country Date 24,617 Great Britain A. D. 1903 900,758 France July 9, 1945 OTHER REFERENCES Amer. Dyestufi Reporter, May 12, 1952, p. 312. 1 Proc. of Am. Assoc. of Textile Chem. and Colorists, pp. 546-547. 

1. IN THE ART OF TREATING TEXTILE MATERIAL IN CONTINUOUS LENGTH WITH AN AQUEOUS LIQUOR SELECTED FROM THE GROUP CONSISTING OF DYEING AND DYE REDUCING LIQUORS AND WHEREIN THE TEXTILE MATERIAL IS PENETRABLE BY SAID AQUEOUS LIQUOR, THE STEPS WHICH COMPRISES CONTINUOUSLY PASSING SAID TEXTILE MATERIAL, WITHOUT FIRST PASSING THE SAME THROUGH A BATH OF MOLTEN METAL WHEREBY THE TEXTILE MATERIAL WILL BE FREE OF METAL PENETRATIONS AND ADHESIONS, THROUGH A FLUID LAYER OF SAID AQUEOUS LIQUOR FLOATING ON A BATH OF MOLTEN METAL WHICH DOES NOT CHEMICALLY REACT WITH SAID TEXTILE MATERIAL AND THE AQUEOUS LIQUOR THEREON, PASSING THE TEXTILE MATERIAL DIRECTLY FROM THE AQUEOUS LIQUOR INTO SAID MOLTEN METAL BATH WITHOUT EXPOSURE TO THE ATMOSPHERE, AND CONTINUOUSLY PASSING THE TREATED TEXTILE MATERIAL DOWNWARDLY TO A SUBSTANTIAL DEPTH, LATERALLY AND UPWARDLY IN A CONTINUOUS MOLTEN METAL PATH, WHEREBY AQUEOUS LIQUOR TAKEN UP BY THE TEXTILE MATERIAL AS THE LATTER TRAVELS THROUGH THE FLOATING LAYER MAY BE SUBJECTED DURING ITS PASSAGE THROUG SAID PATH OF MOLTEN METAL TO CHEMICAL REACTION, PENETRATION AND UNIFORM SQUEEZING DUE TO THE TEMPERATURE AND THE PRESSURE OF THE MOLTEN METAL, THE MELTING POINT OF THE METAL OF THE MOLTEN METAL BATH BEING NOT MORE THAN ABOUT 100* C. AND THE MOLTEN METAL HAVING A TEMPERATURE BELOW THAT AT WHICH SUBSTANTIAL EBULLITION OF THE AQUEOUS LIQUOR OCCURS. 